The present disclosure herein relates to semiconductor memory devices and, more particularly, to non-volatile semiconductor memory devices.
Semiconductor memory devices may generally be classified as volatile or non-volatile memory devices. Volatile semiconductor memory devices lose stored data when a power supply to the memory device is interrupted. Non-volatile semiconductor memory devices can retain data even when the power supply to the device is interrupted. Flash memory devices are one well known type of non-volatile semiconductor memory that may be highly integrated and which may have the advantages of both an EPROM (Erasable Programmable Read Only Memory) device which is capable of programming and erasing data, and of an EEPROM (Electrically Erasable Programmable Read Only Memory) which is capable of electrically programming and erasing data.
A flash memory may have a floating gate and a control gate, which may be sequentially stacked. The floating gate is used for storing data and the control gate is used for controlling the data that is stored in the floating gate. The height of the floating gate, however, may act as an impediment to further scaling down the size of a highly integrated flash memory device. Consequently, flash memory devices that include charge trap layers have been developed to reduce the height of each memory cell therein.